Refrigeration air conditioner ammonia and fluorine combined system and use method

Abstract

The application discloses a kind of refrigeration air conditioner ammonia fluorine combined system and use method, belong to refrigeration air conditioning technical field, including ammonia refrigeration unit one, ammonia refrigeration unit two, circulating bucket one, circulating bucket two, high-pressure liquid accumulator, plate heat exchanger, workshop air conditioner;Ammonia refrigeration unit one suction end and circulating bucket one are communicated, the ammonia refrigeration unit two suction end and the connecting end between ammonia refrigeration unit one and circulating bucket one are communicated, the liquid supply end of circulating bucket one and the liquid inlet end of plate heat exchanger are communicated, back gas end and plate heat exchanger back gas end are communicated, the liquid supply end of circulating bucket two and the liquid inlet end of circulating bucket one are communicated, the liquid supply end of high-pressure liquid accumulator and the connecting end between circulating bucket two and circulating bucket one are communicated, closed circulation pipeline is formed between plate heat exchanger and workshop air conditioner.Can make workshop refrigeration cooling effect promotion, temperature stability reaches standard, energy consumption reduces;System operation safety, avoid ammonia liquid to the harm of personnel.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration and air conditioning technology, specifically relating to a combined ammonia and fluorine system for refrigeration and air conditioning and its usage method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the food production and processing industry, there are strict quality control requirements for the ambient temperature at the production site. The industry generally uses air conditioning to meet the temperature regulation needs. However, existing air conditioning systems have many problems in practical applications and are difficult to adapt to the actual temperature requirements of production.

[0004] The existing workshop air conditioning system is equipped with multiple Freon screw compressors. This refrigeration system exhibits significant insufficient cooling performance. Even with all units running, the highest workshop temperature still fails to reach below 12°C, which is required by the production process. This high-temperature environment not only fails to meet production standards but also severely impacts product quality and related audit requirements. Furthermore, the simultaneous operation of multiple units leads to excessive energy consumption. To achieve cooling requirements, the equipment operates at full load for extended periods, especially during the hot summer months, resulting in a high failure rate. This further complicates cooling efforts and incurs substantial equipment maintenance costs, creating a vicious cycle.

[0005] Overall, the mainstream air conditioning cooling methods currently used in food production and processing enterprises generally suffer from problems such as unsatisfactory cooling effect, excessive energy consumption, and high equipment failure rate. Ultimately, this results in the inability to meet the temperature requirements at the production site, and the product quality failing to meet safety requirements, making it difficult to adapt to the production needs of the food processing industry. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a combined ammonia and fluorine refrigeration system for refrigeration and air conditioning, and its usage method, which can improve the cooling effect of workshops, ensure stable and compliant temperatures, and reduce energy consumption; the system is safe to operate and avoids the harm of ammonia to personnel.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A combined ammonia and fluorine refrigeration and air conditioning system includes an ammonia refrigeration unit 1, an ammonia refrigeration unit 2, a circulating tank 1, a circulating tank 2, a high-pressure liquid receiver, a plate heat exchanger, and a workshop air conditioner. The suction end of ammonia refrigeration unit one is connected to circulation tank one. The suction end of ammonia refrigeration unit two is connected to the connection end between ammonia refrigeration unit one and circulation tank one. The liquid supply end of circulation tank one is connected to the liquid inlet end of plate heat exchanger, and the return end is connected to the return end of plate heat exchanger. The liquid supply end of circulation tank two is connected to the liquid inlet end of circulation tank one. The liquid supply end of high-pressure liquid storage tank is connected to the connection end between circulation tank two and circulation tank one. The water outlet end of plate heat exchanger is connected to the water inlet end of workshop air conditioner. The water return end of workshop air conditioner is connected to the water inlet end of plate heat exchanger. A closed-loop circulation pipeline is formed between the plate heat exchanger and the workshop air conditioner.

[0008] As a further technical solution, it also includes pipeline one, shut-off valve one, and shut-off valve two. The suction end of the ammonia refrigeration unit one is connected to the circulation tank one through pipeline one. The shut-off valve one is located near the suction end of the ammonia refrigeration unit one on pipeline one, and the shut-off valve two is located near the circulation tank on pipeline one.

[0009] As a further technical solution, it also includes pipeline 2 and shut-off valve 9. The suction end of the ammonia refrigeration unit 2 is connected to pipeline 1 through pipeline 2, and the shut-off valve 9 is located near the suction end of the ammonia refrigeration unit 2 in pipeline 2.

[0010] As a further technical solution, it also includes pipe five, pipe four, shut-off valve five, shut-off valve six, and shut-off valve four. The liquid supply end of the circulation tank one is connected to the liquid inlet end of the plate heat exchanger through pipe five, and shut-off valve five is installed on pipe five. The gas return end of the plate heat exchanger is connected to the gas return end of the circulation tank one through pipe four. Shut-off valve six is ​​installed near the gas return end of the plate heat exchanger on pipe four, and shut-off valve four is installed near the gas return end of the circulation tank one on pipe four.

[0011] As a further technical solution, it also includes pipeline six, shut-off valve eleven, and shut-off valve eight. The liquid supply end of the circulation tank two is connected to the liquid inlet end of the circulation tank one through pipeline six. The shut-off valve eleven is located near the liquid supply end of the circulation tank two in pipeline six, and the shut-off valve eight is located near the liquid inlet end of the circulation tank one in pipeline six.

[0012] As a further technical solution, it also includes pipeline three, shut-off valve ten, and shut-off valve seven. The liquid supply end of the high-pressure liquid storage tank is connected to pipeline six through pipeline three. The shut-off valve ten is located near the liquid supply end of the high-pressure liquid storage tank in pipeline three, and the shut-off valve seven is located near the connection point of pipeline three and pipeline six. It also includes shut-off valve three, which is located on the hot ammonia gas pipeline connected to the plate heat exchanger.

[0013] As a further technical solution, it also includes pipe seven, butterfly valve one, and butterfly valve three. The outlet end of the plate heat exchanger is connected to the inlet end of the workshop air conditioner through pipe seven. Butterfly valve one is located near the outlet end of the plate heat exchanger in pipe seven, and butterfly valve three is located at the connection between pipe seven and the inlet end of the workshop air conditioner.

[0014] As a further technical solution, it also includes pipe eight, butterfly valve two, and butterfly valve four. The return water end of the workshop air conditioner is connected to the inlet end of the plate heat exchanger through pipe eight. Butterfly valve two is located near the inlet end of the plate heat exchanger on pipe eight, and butterfly valve four is located at the connection between pipe eight and the return water end of the workshop air conditioner. It also includes ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three, which are connected in parallel between butterfly valve two and butterfly valve four on pipe eight.

[0015] As a further technical solution, the hot ammonia gas pipeline is the oil flushing and cleaning pipe of the plate heat exchanger, and the shut-off valve controls the opening and closing of the oil flushing and cleaning pipe. The oil flushing and cleaning pipe is used to perform oil flushing, cleaning and maintenance on the plate heat exchanger.

[0016] A method for using a combined ammonia and fluorine refrigerant system for refrigeration and air conditioning includes the following steps: First, check the valve status and configure the path. Open the ethylene glycol inlet butterfly valve and ethylene glycol outlet butterfly valve of the plate heat exchanger, as well as the inlet butterfly valve and outlet butterfly valve of the workshop air conditioner. Open the suction shut-off valves of ammonia refrigeration unit one and ammonia refrigeration unit two. Close the liquid supply shut-off valve of circulation tank two to circulation tank one, the standby liquid supply shut-off valve of the high-pressure liquid receiver, and the shut-off valve on the hot ammonia gas pipeline. Then, start the refrigerant circulation and start ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three to form a closed loop, so that the system pressure is stabilized within the preset range and the system continues to run to eliminate air blockage. Next, the refrigeration unit is put into operation and refrigerant is introduced. The ammonia refrigeration unit one and ammonia refrigeration unit two are started. After the units are running smoothly, the liquid supply stop valve from the circulation tank one to the plate heat exchanger is slowly opened, and then the liquid supply stop valve from the circulation tank two to the circulation tank one is slowly opened. Finally, the system parameters are adjusted and stabilized. The opening of the liquid supply shut-off valve is adjusted to stabilize the suction pressure of the ammonia refrigeration unit within the preset range, and the liquid level in the circulation tank is maintained within the range set by the sight glass until the ethylene glycol outlet temperature reaches the process set value and remains stable, thus completing the start-up. At the same time, the operating mode can be adjusted according to the season. In winter, a single ammonia refrigeration unit is turned on; in spring and autumn, two ammonia refrigeration units are turned on; and in summer, two ammonia refrigeration units are turned on and fluorinated refrigeration units are used for auxiliary operation.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: In this invention, ammonia refrigeration unit one and ammonia refrigeration unit two work together as the core cold source of the system, providing continuous and efficient cooling power. Circulation tank two provides a stable liquid supply to circulation tank one, while circulation tank one precisely buffers and regulates the liquid ammonia supply to ensure the continuity and stability of the liquid supply to the plate heat exchanger. After entering the plate heat exchanger, the liquid ammonia completes efficient heat exchange with ethylene glycol, achieving rapid cooling of the ethylene glycol. The cooled ethylene glycol is then driven in parallel by ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three, and stably transported to the workshop air conditioning system through a closed-loop pipeline. Each ethylene glycol pump ensures stable pressure and flow rate of the refrigerant circulation, ensuring continuous and uniform transfer of cooling capacity to the workshop. Each shut-off valve and butterfly valve works together to regulate the on / off of each pipeline and the flow rate of the medium, precisely matching the cooling demand, achieving efficient transfer and regulation of cooling capacity, improving the cooling effect of the workshop, and ensuring that the temperature can be stably maintained to meet the production process requirements for a long period of time.

[0018] This invention utilizes ammonia refrigeration unit one and ammonia refrigeration unit two, which can flexibly adjust their operating modes according to seasonal needs, avoiding energy consumption. The plate heat exchanger achieves efficient heat exchange between ammonia and ethylene glycol, improving cooling capacity conversion efficiency and reducing cooling capacity loss. Circulation tank one and circulation tank two work together to regulate the liquid ammonia supply, matching the heat exchange requirements of the plate heat exchanger and avoiding cooling capacity waste and increased compressor load caused by excessive liquid supply. Ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three are connected in parallel, ensuring refrigerant circulation while allowing for on-demand adjustment, avoiding energy consumption losses from high-load operation of a single pump and reducing energy consumption. Through ethylene glycol, cooling capacity is transferred across regions. The coordination between the various liquid storage, refrigeration, and heat exchange components on the ammonia side and the transportation and heat exchange components on the ethylene glycol side effectively avoids safety hazards to workshop personnel caused by ammonia leakage, ensuring personnel safety during system operation. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a diagram of the refrigeration and air conditioning ammonia-fluorine combined system of the present invention; In the diagram: 1. Ammonia refrigeration unit one; 2. Shut-off valve one; 3. Shut-off valve two; 4. Circulation tank one; 5. Shut-off valve three; 6. Shut-off valve four; 7. Shut-off valve five; 8. Plate heat exchanger; 9. Shut-off valve six; 10. Shut-off valve seven; 11. Shut-off valve eight; 12. Shut-off valve nine; 13. Ammonia refrigeration unit two; 14. Shut-off valve ten; 15. Circulation tank two; 16. Shut-off valve eleven; 17. High-pressure liquid receiver; 18. Pipeline one; 19. Pipeline two; 20. Pipeline three; 21. Pipeline four; 22. Pipeline five; 23. Pipeline six; 24. Butterfly valve one; 25. Butterfly valve two; 26. Ethylene glycol pump one; 27. Ethylene glycol pump two; 28. Ethylene glycol pump three; 29. ​​Butterfly valve three; 30. Workshop air conditioner; 31. Butterfly valve four; 32. Pipeline seven; 33. Pipeline eight. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] The existing workshop air conditioning system is equipped with multiple Freon screw compressors. This refrigeration system exhibits significant shortcomings in cooling performance. Even with all units running, the highest workshop temperature still fails to reach below 12°C, the requirement for production processes. This high-temperature environment not only fails to meet production standards but also severely impacts product quality and related audit requirements. Furthermore, the simultaneous operation of multiple units leads to excessive energy consumption. To achieve cooling, the equipment operates at full capacity for extended periods, especially during the hot summer months, resulting in frequent equipment failures. This further complicates cooling and incurs high maintenance costs, creating a vicious cycle. Overall, the mainstream air conditioning cooling methods currently used in food processing enterprises generally suffer from unsatisfactory cooling performance, excessive energy consumption, and high equipment failure rates. Ultimately, this leads to unmet production temperature requirements, substandard product quality, and a failure rate, making them unsuitable for the production needs of the food processing industry.

[0023] Example 1: The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a combined ammonia and fluorine refrigerant system for refrigeration and air conditioning, such as... Figure 1 As shown, it includes ammonia refrigeration unit 1, ammonia refrigeration unit 2 13, circulating tank 1 4, circulating tank 2 15, high-pressure liquid receiver 17, plate heat exchanger 8, and workshop air conditioner 30.

[0024] The suction end of ammonia refrigeration unit 1 is connected to circulation tank 4, and the suction end of ammonia refrigeration unit 2 13 is connected to the connection between ammonia refrigeration unit 1 and circulation tank 4. The liquid supply end of circulation tank 4 is connected to the liquid inlet end of plate heat exchanger 8, and the return end is connected to the return end of plate heat exchanger 8. The liquid supply end of circulation tank 2 15 is connected to the liquid inlet end of circulation tank 4, and the liquid supply end of high-pressure liquid receiver 17 is connected to the connection between circulation tank 2 15 and circulation tank 4. The water outlet end of plate heat exchanger 8 is connected to the water inlet end of workshop air conditioner 30, and the water return end of workshop air conditioner 30 is connected to the water inlet end of plate heat exchanger 8, forming a closed-loop circulation pipeline between plate heat exchanger 8 and workshop air conditioner 30.

[0025] Specifically, ammonia refrigeration unit 1 and ammonia refrigeration unit 2 work together as the core cold source of the system, providing continuous and efficient cooling power. Circulation tank 2 15 provides a stable liquid supply to circulation tank 4, and circulation tank 4 precisely buffers and regulates the liquid ammonia supply to ensure the continuity and stability of the liquid supply to plate heat exchanger 8. After entering plate heat exchanger 8, the liquid ammonia completes efficient heat exchange with ethylene glycol, achieving rapid cooling of the ethylene glycol. The cooled ethylene glycol is then driven in parallel by ethylene glycol pumps 1 26, 27, and 3 28, and stably transported to the workshop air conditioner 30 through a closed-loop pipeline. Each ethylene glycol pump ensures stable pressure and flow rate of the refrigerant circulation, ensuring continuous and uniform cooling to the workshop. Each shut-off valve and butterfly valve works together to regulate the on / off state of each pipeline and the flow rate of the medium, precisely matching the cooling demand, achieving efficient cooling transfer and regulation, improving the cooling effect of the workshop, and ensuring that the temperature can be stably maintained to meet the production process requirements for a long period.

[0026] Ammonia refrigeration unit 1 and ammonia refrigeration unit 2 can work together to flexibly adjust their operating modes according to seasonal needs, avoiding energy consumption. Plate heat exchanger 8 achieves efficient heat exchange between ammonia and ethylene glycol, improving the efficiency of cold energy conversion and reducing cold energy loss. Circulation tank 1 4 and circulation tank 2 15 work together to regulate the liquid ammonia supply, matching the heat exchange requirements of plate heat exchanger 8, avoiding cold energy waste and increased compressor load caused by excessive liquid supply. Ethylene glycol pumps 1 26, 27, and 3 28 are set up in parallel, ensuring the circulation of the refrigerant while allowing for on-demand adjustment, avoiding energy consumption losses from high-load operation of a single pump, and reducing energy consumption. Cold energy is transferred across regions via ethylene glycol. The coordination between the various liquid storage, refrigeration, and heat exchange components on the ammonia side and the transportation and heat exchange components on the ethylene glycol side effectively avoids safety hazards to workshop personnel caused by ammonia leakage, ensuring personnel safety during system operation.

[0027] It also includes pipe 18, shut-off valve 12, and shut-off valve 23. The suction end of ammonia refrigeration unit 11 is connected to circulation tank 4 via pipe 18. Shut-off valve 2 is located near the suction end of ammonia refrigeration unit 11 on pipe 18, and shut-off valve 23 is located near circulation tank 4 on pipe 18. It also includes pipe 219 and shut-off valve 912. The suction end of ammonia refrigeration unit 213 is connected to pipe 18 via pipe 219, and shut-off valve 912 is located near the suction end of ammonia refrigeration unit 213 on pipe 219.

[0028] Specifically, the suction end of ammonia refrigeration unit 1 is connected to circulation tank 4 via pipeline 18, stop valve 12, and stop valve 23, while the suction end of ammonia refrigeration unit 213 is connected to pipeline 18 via pipeline 219 and stop valve 912. The two ammonia refrigeration units work together to provide a continuous and efficient cooling source for the system. The dual units can flexibly adjust the cooling output according to cooling demand, ensuring a sufficient supply of cooling source from the beginning. Circulation tank 215 supplies liquid stably to circulation tank 4 via pipeline 623, stop valve 811, and stop valve 1116, while high-pressure liquid receiver 17 serves as a backup liquid supply via pipeline 320, stop valve 710, and stop valve 1014. Circulation tank 4 achieves precise and stable liquid level through dual-path liquid supply, and then supplies liquid quantitatively to plate heat exchanger 8 via pipeline 522 and stop valve 57, ensuring the continuity and uniformity of liquid ammonia supply and avoiding heat exchange fluctuations caused by supply fluctuations.

[0029] After heat exchange in plate heat exchanger 8, liquid ammonia is stably returned to circulating tank 4 via pipeline 21, shut-off valve 6, and shut-off valve 9, forming a highly efficient closed-loop circulation on the ammonia side, achieving rapid and sufficient heat exchange between liquid ammonia and ethylene glycol. The cooled ethylene glycol is then transported to workshop air conditioning unit 30 via pipeline 32, butterfly valve 24, and butterfly valve 29. After heat exchange, the ethylene glycol is returned via pipeline 33, butterfly valve 25, and butterfly valve 31. Parallel ethylene glycol pumps 26, 27, and 38 provide stable pressure and flow rate for the ethylene glycol circulation, ensuring a continuous and uniform delivery of cooled ethylene glycol to workshop air conditioning unit 30, allowing for rapid cooling of the workshop.

[0030] It also includes pipe 522, pipe 421, shut-off valve 57, shut-off valve 69, and shut-off valve 46. The liquid supply end of the circulation tank 14 is connected to the liquid inlet end of the plate heat exchanger 8 through pipe 522, and shut-off valve 57 is installed on pipe 522. The gas return end of the plate heat exchanger 8 is connected to the gas return end of the circulation tank 14 through pipe 421, shut-off valve 69 is installed near the gas return end of the plate heat exchanger 8 on pipe 421, and shut-off valve 46 is installed near the gas return end of the circulation tank 14 on pipe 421.

[0031] Specifically, ammonia refrigeration units 1 and 2 replace the original Freon units as the main cold source. With independent flow control via pipelines 18 and 29 and their corresponding shut-off valves, the number of units in operation can be flexibly adjusted according to the season and workshop refrigeration needs. A single unit operates in winter, while two units operate in spring and autumn, reducing basic energy consumption. Circulation tanks 4 and 2 precisely regulate the liquid ammonia supply to the plate heat exchanger 8 via pipeline 23 and shut-off valves 8 and 116. The high-pressure liquid receiver 17 serves only as a backup supply, avoiding a sudden increase in compressor suction pressure and wasted cooling capacity caused by excessive liquid ammonia supply, thus reducing the operating load of the ammonia refrigeration units.

[0032] Plate heat exchanger 8, in conjunction with the ammonia-side circulation of pipes 5 (22) and 4 (21), achieves efficient heat exchange between liquid ammonia and ethylene glycol, improving the efficiency of cold energy conversion and reducing cold energy loss in the heat exchange process. Ethylene glycol pumps 1 (26), 2 (27), and 3 (28) are connected in parallel between butterfly valves 2 (25) and 4 (31) on pipe 8 (33), allowing for flexible start-up and shutdown according to ethylene glycol circulation needs, avoiding energy consumption losses from high-load operation of a single pump. Simultaneously, butterfly valves 1 (24), 2 (25), 3 (29), and 4 (31) precisely regulate the ethylene glycol delivery flow rate, ensuring that the refrigerant circulation always matches the workshop's refrigeration needs, avoiding energy waste caused by ineffective circulation.

[0033] It also includes pipe 6.23, shut-off valve 11.16, and shut-off valve 8.11. The supply end of circulation tank 2.15 is connected to the inlet end of circulation tank 1.4 via pipe 6.23. Shut-off valve 11.16 is located near the supply end of circulation tank 2.15 on pipe 6.23, and shut-off valve 8.11 is located near the inlet end of circulation tank 1.4 on pipe 6.23. It also includes pipe 3.20, shut-off valve 10.14, and shut-off valve 7.10. The supply end of high-pressure liquid receiver 17 is connected to pipe 6.23 via pipe 3.20. Shut-off valve 10.14 is located near the supply end of high-pressure liquid receiver 17 on pipe 3.20, and shut-off valve 7.10 is located near the connection point of pipe 6.23 on pipe 3.20. It also includes shut-off valve 3.5, which is located on the hot ammonia gas pipeline connected to plate heat exchanger 8.

[0034] Specifically, the circulation of liquid ammonia is only limited to the ammonia-side closed pipeline composed of ammonia refrigeration unit 1, ammonia refrigeration unit 2 13, circulation barrel 1 4, circulation barrel 2 15, high-pressure liquid storage tank 17 and plate heat exchanger 8. Pipeline 1 18, pipeline 2 19, pipeline 3 20, pipeline 4 21, pipeline 5 22, pipeline 6 23 and the corresponding stop valves form an ammonia-side closed flow control system to ensure that liquid ammonia always flows in the closed pipeline in the machine room and does not contact the workshop area with dense personnel. The plate heat exchanger 8 serves as the only heat exchange interface between the ammonia side and the ethylene glycol side, only realizing the indirect heat exchange between liquid ammonia and ethylene glycol, and eliminating the possibility of liquid ammonia directly entering the ethylene glycol pipeline. The cooled ethylene glycol, as a secondary refrigerant, forms an independent closed circulation pipeline through pipeline 7 32, pipeline 8 33 and the corresponding butterfly valves, and is transported to the workshop air conditioner 30 under the drive of ethylene glycol pump 1 26, ethylene glycol pump 2 27, and ethylene glycol pump 3 28 to complete workshop refrigeration. The ethylene glycol-side pipeline is completely physically isolated from the ammonia-side pipeline, only realizing the cross-regional transfer of cold quantity, and there is no passage for ammonia liquid to enter the workshop.

[0035] At the same time, the hot ammonia gas pipeline and stop valve 3 5 supporting the plate heat exchanger 8 are only opened during the cleaning and maintenance of the plate heat exchanger 8, and the whole operation is carried out in the machine room without affecting the workshop area. The coordinated design of all components and pipelines on the ammonia side and the conveying components on the ethylene glycol side and the workshop air conditioner 30 effectively avoids the safety hazards caused by ammonia liquid leakage to workshop operators and ensures the safety of personnel in the whole process of system operation.

[0036] It also includes pipeline 7 32, butterfly valve 1 24, and butterfly valve 3 29. The water outlet end of the plate heat exchanger 8 is connected to the water inlet end of the workshop air conditioner 30 through pipeline 7 32, the butterfly valve 1 24 is arranged near the water outlet end of the plate heat exchanger 8 on pipeline 7 32, and the butterfly valve 3 29 is arranged at the connection between pipeline 7 32 and the water inlet end of the workshop air conditioner 30. It also includes pipeline 8 33, butterfly valve 2 25, and butterfly valve 4 31. The return water end of the workshop air conditioner 30 is connected to the water inlet end of the plate heat exchanger 8 through pipeline 8 33, the butterfly valve 2 25 is arranged near the water inlet end of the plate heat exchanger 8 on pipeline 8 33, and the butterfly valve 4 31 is arranged at the connection between pipeline 8 33 and the return water end of the workshop air conditioner 30. It also includes ethylene glycol pump 1 26, ethylene glycol pump 2 27, and ethylene glycol pump 3 28, which are connected in parallel between the butterfly valve 2 25 and the butterfly valve 4 31 on pipeline 8 33. The hot ammonia gas pipeline is the flushing oil pipeline of the plate heat exchanger 8, and the stop valve 3 5 controls the on-off of the flushing oil pipeline, and the flushing oil pipeline is used for flushing and maintaining the plate heat exchanger 8.

[0037] Specifically, the plate heat exchanger 8 is connected to a dedicated hot ammonia gas pipeline, which serves as the flushing oil pipeline and is independently controlled by the stop valve 3 5 for on-off. When the plate heat exchanger 8 is dirty and blocked, affecting the heat exchange efficiency, the stop valve 3 5 can be opened to allow hot ammonia gas to enter the plate heat exchanger 8 through the flushing oil pipeline, completing the flushing and maintenance of the plate heat exchanger 8. The cleaning operation can be realized without disassembling the equipment, and the operation is convenient.

[0038] Meanwhile, each pipeline is equipped with an independent shut-off valve or butterfly valve. When a pipeline or component in the system requires maintenance, the corresponding valve can be closed to achieve independent flow interruption for that section, without affecting the temporary operation of other components in the system, significantly reducing the impact of maintenance on workshop refrigeration. Ethylene glycol pumps 1-26, 2-27, and 3-28 adopt a parallel design. If one pump fails, the others can immediately take over, ensuring uninterrupted ethylene glycol circulation and further improving system stability. The maintenance design and coordination of each component allow the system to maintain high-efficiency heat exchange and cooling effects over a long period, reducing refrigeration interruptions caused by equipment failure or blockage.

[0039] Example 2: Based on Example 1, this example provides a method for using a combined ammonia and fluorine refrigerant system for refrigeration and air conditioning, including the following steps: First, check the valve status and configure the path. Open the ethylene glycol inlet butterfly valve 25 and ethylene glycol outlet butterfly valve 24 of plate heat exchanger 8, and the inlet butterfly valve 29 and outlet butterfly valve 31 of workshop air conditioner 30. Open the suction shut-off valve 2 and shut-off valve 9 of ammonia refrigeration unit 1 and ammonia refrigeration unit 2 13. Close the liquid supply shut-off valves 8 11 and 11 16 from circulation tank 2 15 to circulation tank 1 4, the standby liquid supply shut-off valves 7 10 and 11 14 of high-pressure liquid receiver 17, and the shut-off valve 3 5 on the hot ammonia gas pipeline. Then, start the refrigerant circulation by starting ethylene glycol pump 26, ethylene glycol pump 27, and ethylene glycol pump 3 28 to form a closed loop, stabilizing the system pressure within the preset range and continuing operation to eliminate air locks.

[0040] Next, put the refrigeration unit into operation and introduce refrigerant. Start ammonia refrigeration unit 1 and ammonia refrigeration unit 2. After the units are running smoothly, slowly open the liquid supply shut-off valve 5 7 of the circulation tank 1 4 to the plate heat exchanger 8, and then slowly open the liquid supply shut-off valve 8 11 and shut-off valve 16 of the circulation tank 2 15 to the circulation tank 1 4.

[0041] Finally, system parameters are adjusted and stabilized. The opening of the liquid supply shut-off valve is adjusted to stabilize the suction pressure of the ammonia refrigeration unit within the preset range, and the liquid level in the circulating tank is maintained within the range set by the sight glass until the ethylene glycol outlet temperature reaches the process set value and remains stable, thus completing the start-up. The operating mode can also be adjusted according to the season: one ammonia refrigeration unit is operated in winter, two ammonia refrigeration units are operated in spring and autumn, and two ammonia refrigeration units are operated in summer with the assistance of a refrigerant refrigeration unit.

[0042] Specifically, step 1: Check the physical status of all butterfly valves in the ethylene glycol circulation pipeline, and confirm that the ethylene glycol inlet butterfly valve 25 and outlet butterfly valve 24 of the plate heat exchanger 8 are in the open state; the inlet butterfly valve 29 and outlet butterfly valve 31 of the workshop air conditioning 30 pipeline are in the open state.

[0043] Check the connection status of the ammonia refrigerant pipeline, and confirm that the suction shut-off valves 1-2, 9-12, and 2-3 of ammonia refrigeration unit 1 and ammonia refrigeration unit 2 are in the open position; confirm that the shut-off valves 8-11 and 11-16 on the liquid supply pipeline of circulation tank 1-4 are in the closed position, and the shut-off valves 10-14 and 7-10 are in the closed position, and use the high-pressure liquid receiver 17 as a backup liquid supply; confirm that the shut-off valve 3-5 on the hot ammonia defrost pipeline is in the closed position, and eliminate interference from non-operation mode.

[0044] Step 2: Start ethylene glycol pump 1 (26), ethylene glycol pump 2 (27), and ethylene glycol pump 3 (28) to form a closed loop; observe the outlet pressure gauges of the ethylene glycol pumps sequentially to confirm that the system pressure is stably established within the range of 0.5MPa ± 0.05MPa; continue running for 3... Allow 5 minutes to allow the ethylene glycol solution to fully fill the entire circulation pipeline, eliminating air blockages and establishing a uniform temperature and pressure field. During this period, do not start any refrigeration compressor units or open the liquid supply valve.

[0045] Step 3: Start ammonia refrigeration unit 1 and ammonia refrigeration unit 2; after the ammonia refrigeration units are running smoothly (stable operating current, no abnormal vibration), slowly open shut-off valve 5 7 to allow liquid ammonia to smoothly enter plate heat exchanger 8 to cool the ethylene glycol solution inside; slowly open shut-off valve 8 11 and shut-off valve 11 16 to control the liquid level in circulation tank 4, to avoid a sudden increase in liquid supply that could cause a sudden rise in compressor suction pressure or liquid slugging.

[0046] Step 4: Monitor the suction pressure of ammonia refrigeration unit 1 and ammonia refrigeration unit 2 in real time. Adjust the opening of shut-off valve 8 11 and shut-off valve 16 to stabilize the suction pressure between 0.2 and 0.25 MPa. Monitor the ethylene glycol outlet temperature and confirm that it drops to the process set value and remains stable. Observe the liquid level of circulation tank 4 and maintain it in the range of 1 / 3 to 2 / 3 of the sight glass height. The system enters a stable operating state, and the start-up process is completed.

[0047] Core principle: Liquid ammonia evaporates and absorbs heat in plate heat exchanger 8 to cool ethylene glycol, which is then pumped to the workshop by an ethylene glycol pump. Therefore, the key to operation is to "start the pump (circulation) first, then start the machine (refrigeration); stop the machine (refrigeration) first, then stop the pump (circulation)".

[0048] In this embodiment, multiple operating modes can be adopted according to the season. In winter, only one ammonia refrigeration unit can be operated; in spring and autumn, two ammonia refrigeration units can be operated; and in summer, two ammonia refrigeration units plus a refrigerant refrigeration unit can be operated as auxiliary units to meet production requirements and save energy. Previously, with all five refrigerant LG20 compressors running at full capacity, the highest workshop temperature reached 13 degrees Celsius. At around 16℃, two LG16 ammonia compressors can basically control the maximum temperature below 12℃, resulting in significant energy savings. Stop valve 1014 is designed as a backup liquid supply valve (normally closed), and can only be opened when stop valves 1116 and 811 fail to close during normal liquid supply operation, and the opening degree must not be too large.

[0049] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A combined ammonia and fluorine refrigerant system for refrigeration and air conditioning, characterized in that, Includes ammonia refrigeration unit 1, ammonia refrigeration unit 2, circulating tank 1, circulating tank 2, high-pressure liquid receiver, plate heat exchanger, and workshop air conditioner; The suction end of ammonia refrigeration unit one is connected to circulation tank one. The suction end of ammonia refrigeration unit two is connected to the connection end between ammonia refrigeration unit one and circulation tank one. The liquid supply end of circulation tank one is connected to the liquid inlet end of plate heat exchanger, and the return end is connected to the return end of plate heat exchanger. The liquid supply end of circulation tank two is connected to the liquid inlet end of circulation tank one. The liquid supply end of high-pressure liquid storage tank is connected to the connection end between circulation tank two and circulation tank one. The water outlet end of plate heat exchanger is connected to the water inlet end of workshop air conditioner. The water return end of workshop air conditioner is connected to the water inlet end of plate heat exchanger. A closed-loop circulation pipeline is formed between the plate heat exchanger and the workshop air conditioner.

2. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 1, characterized in that, It also includes pipeline one, shut-off valve one, and shut-off valve two. The suction end of the ammonia refrigeration unit one is connected to the circulation tank one through pipeline one. The shut-off valve one is located near the suction end of the ammonia refrigeration unit one on pipeline one, and the shut-off valve two is located near the circulation tank on pipeline one.

3. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 2, characterized in that, It also includes pipe 2 and shut-off valve 9. The suction end of the ammonia refrigeration unit 2 is connected to pipe 1 through pipe 2, and the shut-off valve 9 is located near the suction end of the ammonia refrigeration unit 2 on pipe 2.

4. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 1, characterized in that, It also includes pipe five, pipe four, shut-off valve five, shut-off valve six, and shut-off valve four. The liquid supply end of the circulation tank one is connected to the liquid inlet end of the plate heat exchanger through pipe five, and shut-off valve five is installed on pipe five. The gas return end of the plate heat exchanger is connected to the gas return end of the circulation tank one through pipe four. Shut-off valve six is ​​installed near the gas return end of the plate heat exchanger on pipe four, and shut-off valve four is installed near the gas return end of the circulation tank one on pipe four.

5. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 1, characterized in that, It also includes pipeline six, shut-off valve eleven, and shut-off valve eight. The liquid supply end of the circulation tank two is connected to the liquid inlet end of the circulation tank one through pipeline six. The shut-off valve eleven is located near the liquid supply end of the circulation tank two in pipeline six, and the shut-off valve eight is located near the liquid inlet end of the circulation tank one in pipeline six.

6. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 5, characterized in that, It also includes pipeline three, shut-off valve ten, and shut-off valve seven. The supply end of the high-pressure liquid storage tank is connected to pipeline six through pipeline three. Shut-off valve ten is located near the supply end of the high-pressure liquid storage tank in pipeline three, and shut-off valve seven is located near the connection point of pipeline three and pipeline six. It also includes shut-off valve three, which is located on the hot ammonia gas pipeline connected to the plate heat exchanger.

7. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 1, characterized in that, It also includes pipe seven, butterfly valve one, and butterfly valve three. The outlet of the plate heat exchanger is connected to the inlet of the workshop air conditioner through pipe seven. Butterfly valve one is located near the outlet of the plate heat exchanger in pipe seven, and butterfly valve three is located at the connection between pipe seven and the inlet of the workshop air conditioner.

8. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 7, characterized in that, It also includes pipe eight, butterfly valve two, and butterfly valve four. The return water end of the workshop air conditioner is connected to the inlet end of the plate heat exchanger through pipe eight. Butterfly valve two is located near the inlet end of the plate heat exchanger on pipe eight, and butterfly valve four is located at the connection between pipe eight and the return water end of the workshop air conditioner. It also includes ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three, which are connected in parallel between butterfly valve two and butterfly valve four on pipe eight.

9. The refrigeration and air conditioning ammonia-fluorine combined system as described in claim 6, characterized in that, The hot ammonia gas pipeline is the oil flushing and cleaning pipeline for the plate heat exchanger. The shut-off valve controls the opening and closing of the oil flushing and cleaning pipeline, which is used for oil flushing, cleaning, and maintenance of the plate heat exchanger.

10. A method of using a refrigeration and air conditioning ammonia-fluorine combined system as described in any one of claims 1-9, characterized in that, Includes the following steps: First, check the valve status and configure the path. Open the ethylene glycol inlet butterfly valve and ethylene glycol outlet butterfly valve of the plate heat exchanger, as well as the inlet butterfly valve and outlet butterfly valve of the workshop air conditioner. Open the suction shut-off valves of ammonia refrigeration unit one and ammonia refrigeration unit two. Close the liquid supply shut-off valve of circulation tank two to circulation tank one, the standby liquid supply shut-off valve of the high-pressure liquid receiver, and the shut-off valve on the hot ammonia gas pipeline. Then, start the refrigerant circulation and start ethylene glycol pump one, ethylene glycol pump two, and ethylene glycol pump three to form a closed loop, so that the system pressure is stabilized within the preset range and the system continues to run to eliminate air blockage. Next, the refrigeration unit is put into operation and refrigerant is introduced. The ammonia refrigeration unit one and ammonia refrigeration unit two are started. After the units are running smoothly, the liquid supply stop valve from the circulation tank one to the plate heat exchanger is slowly opened, and then the liquid supply stop valve from the circulation tank two to the circulation tank one is slowly opened. Finally, the system parameters are adjusted and stabilized. The opening of the liquid supply shut-off valve is adjusted to stabilize the suction pressure of the ammonia refrigeration unit within the preset range, and the liquid level in the circulation tank is maintained within the range set by the sight glass until the ethylene glycol outlet temperature reaches the process set value and remains stable, thus completing the start-up. At the same time, the operating mode can be adjusted according to the season. In winter, a single ammonia refrigeration unit is turned on; in spring and autumn, two ammonia refrigeration units are turned on; and in summer, two ammonia refrigeration units are turned on and fluorinated refrigeration units are used for auxiliary operation.

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